Copper tubing and fittings are used for plumbing in many buildings. The tubing typically comes in ten-foot lengths, which are usually 1/2" or 3/4" in diameter, but may be 3/8", 1" or other diameters. The fittings include elbows and tees. Lengths of tubing and fittings are joined by soldering the joints.
Soldering is a method of joining metals together using a layer of alloy which is applied when molten and then solidifies on cooling. Plumbing work uses soft solder, an alloy of tin and silver with a low melting point.
Soldering requires that mating surfaces of the tubing and/or fittings be free of contaminants, oxides, or other obstructing films so that the surfaces will readily accept the solder. This is required to form sound joints which are free of porosity and voids and which do not leak.
It is common practice, therefore, to clean the outer surfaces of the ends of tubing and the inner surfaces of fittings which will receive the solder. A soldering flux (soldering paste) also is applied to the cleaned surface before soldering. Soldering flux is a chemical substance which aids the flow of solder and serves to remove and prevent the formation of oxides on the pieces to be united by soldering. (A "flux", as used herein, may be any flowable product, such as coatings, pastes, and other flowable products used not only in soldering but in other applications, including but not limited to welding, brazing, glazing, painting, and other such applications.)
Soldering flux is available normally in paste form and is supplied in metal cans containing about two (2) ounces of flux. A small brush (similar to a painting brush) may be used to apply the flux to the external surface or internal surface of the tubing or fitting to be soldered.
Wire brushes usually are used to clean the surfaces before applying the flux. However, sandpaper, steel wire pads, dry steel wool, or emery cloth may be used rather than wire brushes.
Various tools incorporating brushes have been developed to perform the required cleaning operation. Examples of such tools are disclosed in U.S. Pat. Nos. 4,133,070; 4,862,549; 5,269,104; 5,307,534; 5,493,748; and 4,899,409. However, those tools do not include means for dispensing and applying flux (i.e., "fluxing") onto the surfaces of the tubing or fittings after cleaning or prior to soldering.
Conventional cleaning and fluxing of many tubing and fitting joint components can become tedious and time-consuming, which may lead to inattention and error by plumbers. A tool which would enable a plumber to complete the tasks of cleaning and applying flux more quickly and effectively could eliminate tedium and increase safety. For example, having the ability to complete these operations more quickly and effectively would decrease the likelihood of a plumber knocking over his soldering torch, which is set down during cleaning and fluxing operations.
It is desired to have a hand-held tool which combines in one unit the means for quickly and effectively cleaning and fluxing the surfaces of tubing and fittings. It also is desired to have separate tools of this type for various sizes of tubing (e.g., 1", 3/4", 1/2", and 3/8").